The evolution of the H2O maser emission in the accretion burst source G358.93-0.03

Abstract

The massive young stellar object (MYSO) G358.93-0.03-MM1 showed an extraordinary near-infrared- to (sub-)millimetre-dark and far-infrared-loud accretion burst, which is closely associated with flares of several class II methanol maser transitions, and, later, a 22 GHz water maser flare. Water maser flares provide an invaluable insight into ejection events associated with accretion bursts. Although the short timescale of the 22 GHz water maser flare made it impossible to carry out a very long baseline interferometry observation, we could track it with the Karl G. Jansky Very Large Array (VLA). The evolution of the spatial structure of the 22 GHz water masers and their association with the continuum sources in the region is studied with the VLA during two epochs, pre- and post-H2O maser flare. A drastic change in the distribution of the water masers is revealed: in contrast to the four maser groups detected during epoch I, only two newly formed clusters are detected during epoch II. The 22 GHz water masers associated with the bursting source MM1 changed in morphology and emission velocity extent. Clear evidence of the influence of the accretion burst on the ejection from G358.93-0.03-MM1 is presented. The accretion event has also potentially affected a region with a radius of ~2'' (~13 500 AU at 6.75 kpc), suppressing water masers associated with other point sources in this region.

References in corpus (8)

• Trigonometric Parallaxes of Massive Star Forming Regions: VI. Galactic Structure, Fundamental Parameters and Non-Circular Motions
• An extraordinary outburst in the massive protostellar system NGC6334I-MM1: quadrupling of the millimeter continuum
• A heat-wave of accretion energy traced by masers in the G358-MM1 high-mass protostar
• Detection of new methanol maser transitions associated with G358.93-0.03
• Discovery of six new class II methanol maser transitions, including the unambiguous detection of three torsionally excited lines toward G358.931-0.030
• Water maser variability in a high-mass YSO outburst -- VERA and ALMA observations of S255 NIRS 3
• A multi-transition methanol maser study of the accretion burst source G358.93-0.03-MM1
• The Extraordinary Outburst in the Massive Protostellar System NGC6334I-MM1: Spatio-kinematics of Water Masers during a Contemporaneous Flare Event

Cited by in corpus (4)

• A Keplerian disk with a four-arm spiral birthing an episodically accreting high-mass protostar
• The accretion burst of the massive young stellar object G323.46 -0.08
• Identifying the Mechanisms of Water Maser Variability During the Accretion Burst in NGC6334I
• The Effelsberg survey of FU~Orionis and EX~Lupi objects II. -- H${}_2$O maser observations